1. Field of the Invention
The present invention relates to a method of driving a surveillance camera by using a rotary electric machine which is optimum for driving a surveillance camera or the like.
2. Description of the Related Art
In the case of monitoring an important monitor place by a surveillance camera mainly for preventing crime all day long without humans in attendance, a surveillance camera system which can be three-dimensionally positioned is necessary. A surveillance camera is used, which is driven by a panning motor of horizontal rotation and a tilting motor for vertically moving the camera being horizontally driven.
FIG. 4 is a diagram showing the configuration of a conventional surveillance camera which is three-dimensionally positioned. Shown in the diagram are a motor 31 for driving a horizontal shaft, an output pinion 32 of the motor 31, a reduction gear 33 which meshes with the output pinion 32, and a cylindrical shaft 35 for horizontally rotating a camera 10. The cylindrical shaft 35 is supported by upper and lower chassises 42 via bearings 34 having a large inside diameter.
The upper and lower chassises 42 are fixed by pillars 44. Also shown are a tilting motor 37, a pinion 38 of the tilting motor 37, a gear 39 which meshes with the pinion 38, bearings 40, a mounting plate 7, and the camera 10.
If a slip ring is not used, however, after continuously rotating in one direction a plurality of times, a lead cable for supplying power to the tilting motors and the camera is twisted and the camera becomes unable to rotate. Even when the slip ring is used, if the horizontal rotation shaft of the rotary electrical machine and that of the camera are not concentric, the structure is complicated, and the outer shape is large. Consequently, the camera is conspicuous and is not always suited to the purpose of this kind.
There is no surveillance camera system optimum for monitoring an important monitor place by a surveillance camera mainly for crime prevention day and night without humans in attendance, which can automatically monitor the place without humans in attendance and, when something suspicious is found, follow the suspicious without humans in attendance, and accurately monitor the suspicious at high precision. It is therefore an object of the invention to develop a surveillance camera driving method capable of solving the problems.